Jan 14, 2015 (6 years ago)
That's the type I'm familiar with,
yours sounds like the old school dump valve,
pressure increases until a set point dump valve opens to prevent over boost and blowing induction hoses off!
very 80's with the distinctive hiss as the dump valve opens like an old school tuned Scoobie do.
If so then you turbo should be running until the dump valve blows the excessive pressure off.
Can you take off the induction hose off the turbo and run the engine?
Won't run so good but all your looking for is to see if the vanes ARE rotating.
The !,6 hdi's are notorious for this kind of fault,
not too sure if the 1.4;s are the same.
leaking injector seals cause contamination of the oil,
contamination blocks up the oil pathways and particularly the small oil feed/return to and from the turbo.
usually a car killer as the entire engine needs stripped and cleaned to surgical standards and new turbo fitted.
But as stated I'm unsure if the !,4 has the same problem.
Right now you need to find out IF the turbo is spinning round when the engine is running.